Repositório Colecção: DCEA - ARIAChttp://hdl.handle.net/10362/1753
DCEA - ARIACFri, 09 Dec 2016 13:54:09 GMT2016-12-09T13:54:09ZNumerical prediction of diffusion and electric field-induced iron nanoparticle transporthttp://hdl.handle.net/10362/14798
Título: Numerical prediction of diffusion and electric field-induced iron nanoparticle transport
Autor: Gomes, Helena I.; Rodríguez-Maroto, José Miguel; Ribeiro, Alexandra B.; Pamukcu, Sibel; Dias-Ferreira, Celia
Resumo: Zero valent iron nanoparticles (nZVI) are considered very promising for the remediation of contaminated soils and groundwaters. However, an important issue related to their limited mobility remains unsolved. Direct current can be used to enhance the nanoparticles transport, based on the same principles of electrokinetic remediation. In this work, a generalized physicochemical model was developed and solved numerically to describe the nZVI transport through porous media under electric field, and with different electrolytes (with different ionic strengths). The model consists of the Nernst–Planck coupled system of equations, which accounts for the mass balance of ionic species in a fluid medium, when both the diffusion and electromigration of the ions are considered. The diffusion and electrophoretic transport of the negatively charged nZVI particles were also considered in the system. The contribution of electroosmotic flow to the overall mass transport was included in the model for all cases. The nZVI effective mobility values in the porous medium are very low (10−7–10−4 cm2 V−1 s−1), due to the counterbalance between the positive electroosmotic flow and the electrophoretic transport of the negatively charged nanoparticles. The higher the nZVI concentration is in the matrix, the higher the aggregation; therefore, low concentration of nZVI suspensions must be used for successful field application.Sat, 01 Nov 2014 00:00:00 GMThttp://hdl.handle.net/10362/147982014-11-01T00:00:00ZInvaded habitatshttp://hdl.handle.net/10362/4034
Título: Invaded habitats
Autor: Lopez-Vaamonde, Carlos; Glavendekić, Milka; Paiva, Maria Rosa
Resumo: More than 65% (1040 species) of arthropod species alien to Europe are associated
with human-made habitats, especially parks and gardens, human settlements and
agricultural lands, whereas woodlands are yet colonized by less than 20% of the
alien fauna, which still has a negligible representation in the other natural
and semi-natural habitats. Large diff erences in habitat affi nity are observed
between alien taxonomic groups. Phytophagous species are predominant among
aliens, representing 47.2% of species alien to Europe.Fri, 01 Jan 2010 00:00:00 GMThttp://hdl.handle.net/10362/40342010-01-01T00:00:00ZHymenoptera.http://hdl.handle.net/10362/4035
Título: Hymenoptera.
Autor: Rasplus, Jean-Yves; Villemant, Claire; Paiva, Maria Rosa; Delvare, Gérard; Roques, Alain
Editor: Roques, A et al.
Resumo: We present the fi rst review of Hymenoptera alien to Europe. Our study revealed
that nearly 300 species of Hymenoptera belonging to 30 families have been
introduced to Europe. In terms of alien species diversity within invertebrate
orders, this result ranks Hymenoptera third following Coleoptera and Hemiptera.
Two third of alien Hymenoptera are parasitoids or hyperparasitoids that were
mostly introduced for biological control purposes. Only 35 phytophagous species,
47 predator species and 3 species of pollinators have been introduced. Six
families of wasps (Aphelinidae, Encyrtidae, Eulophidae, Braconidae, Torymidae,
Pteromalidae) represent together with ants (Formicidae) about 80% of the alien
Hymenoptera introduced to Europe. Th e three most diverse families are
Aphelinidae (60 species representing 32% of the Aphelinid European fauna),
Encyrtidae (55) and Formicidae (42) while the Chalcidoidea together represents
2/3 of the total Hymenoptera species introduced to Europe. Th e fi rst two
families are associated with mealybugs, a group that also included numerous
aliens to Europe. In addition, they are numerous cases of Hymenoptera introduced
from one part of Europe to another, especially from continental Europe to
British Islands. Th ese introductions mostly concerned phytophagous or gall-
maker species (76 %), less frequently parasitoids. Th e number of new records of
alien Hymenoptera per year has shown an exponential increase during the last 200
years. Th e number of alien species introduced by year reached a maximum of 5
species per year between 1975 and 2000. North America provided the greatest part
of the hymenopteran species alien to Europe (96 species, 35.3%), followed by
Asia (84 species, 30.9%) and Africa (49 species, 18%). Th ree Mediterranean
countries (only continental parts) hosted the largest number of alien
Hymenoptera: Italy (144 spp.), France (111 spp.) and Spain (90 spp.) but no
correlation was found with the area of countries. Intentional introduction,
mostly for biological control, has been the main pathway of introduction for
Hymenoptera. Consequently, the most invaded habitats are agricultural and
horticultural as well as greenhouses. To the contrary, Hymenoptera alien in
Europe are mostly associated with woodland and forest habitats. Ecological and
economic impacts of alien Hymenoptera have been poorly studied. Ants have
probably displaced native species and this is also true for introduced
parasitoids that are suspected to displace native parasitoids by competition,
but reliable examples are still scarce. Th e cost of these impacts has never
been estimated.Fri, 01 Jan 2010 00:00:00 GMThttp://hdl.handle.net/10362/40352010-01-01T00:00:00ZThe saltopteran fauna of Portugal: new records and biogeographical aspects
(Orthopteroidea)http://hdl.handle.net/10362/4033
Título: The saltopteran fauna of Portugal: new records and biogeographical aspects
(Orthopteroidea)
Autor: Schmidt, Gerhard H; Martinho, Ana Paula; Paiva, Maria RosaThu, 01 Jan 2009 00:00:00 GMThttp://hdl.handle.net/10362/40332009-01-01T00:00:00Z